Their friendships are unstable.
Since first graders are just beginning to develop their social skills, there will invariably be bumps in the road. They are often mean to other kids, they have little sense of loyalty, they can be bossy, and they can become tattletales.
What you should do: Talk with your child about what it means to be a good friend and how to get along well with others. Even first graders can understand these concepts and talk about them.